address feedback

Author: mejrs

compiler/rustc_attr_parsing/src/attributes/diagnostic/mod.rs

@@ -118,9 +118,9 @@ fn parse_directive_items<'p, S: Stage>(
         }}
 
         macro or_malformed($($code:tt)*) {{
-            let Some(ret) = (try {
-                $($code)*
-            }) else {
+            let Some(ret) = (||{
+                Some($($code)*)
+            })() else {
 
                 malformed!()
             };

compiler/rustc_attr_parsing/src/attributes/diagnostic/on_const.rs

@@ -12,8 +12,10 @@ pub(crate) struct OnConstParser {
 }
 
 impl<S: Stage> AttributeParser<S> for OnConstParser {
-    const ATTRIBUTES: AcceptMapping<Self, S> =
-        &[(&[sym::diagnostic, sym::on_const], template!(Word), |this, cx, args| {
+    const ATTRIBUTES: AcceptMapping<Self, S> = &[(
+        &[sym::diagnostic, sym::on_const],
+        template!(List: &[r#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#]),
+        |this, cx, args| {
             if !cx.features().diagnostic_on_const() {
                 return;
             }
@@ -47,7 +49,10 @@ impl<S: Stage> AttributeParser<S> for OnConstParser {
                 return;
             };
             merge_directives(cx, &mut this.directive, (span, directive));
-        })];
+        },
+    )];
+
+    //FIXME Still checked in `check_attr.rs`
     const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(ALL_TARGETS);
 
     fn finalize(self, _cx: &FinalizeContext<'_, '_, S>) -> Option<AttributeKind> {

compiler/rustc_attr_parsing/src/attributes/diagnostic/on_unimplemented.rs

@@ -57,9 +57,13 @@ impl OnUnimplementedParser {
 
 impl<S: Stage> AttributeParser<S> for OnUnimplementedParser {
     const ATTRIBUTES: AcceptMapping<Self, S> = &[
-        (&[sym::diagnostic, sym::on_unimplemented], template!(Word), |this, cx, args| {
-            this.parse(cx, args, Mode::DiagnosticOnUnimplemented);
-        }),
+        (
+            &[sym::diagnostic, sym::on_unimplemented],
+            template!(List: &[r#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#]),
+            |this, cx, args| {
+                this.parse(cx, args, Mode::DiagnosticOnUnimplemented);
+            },
+        ),
         (
             &[sym::rustc_on_unimplemented],
             template!(List: &[r#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#]),
@@ -68,6 +72,7 @@ impl<S: Stage> AttributeParser<S> for OnUnimplementedParser {
             },
         ),
     ];
+    //FIXME attribute is not parsed for non-traits but diagnostics are issued in `check_attr.rs`
     const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(ALL_TARGETS);
 
     fn finalize(self, _cx: &FinalizeContext<'_, '_, S>) -> Option<AttributeKind> {

compiler/rustc_attr_parsing/src/lib.rs

@@ -80,7 +80,6 @@
 #![cfg_attr(bootstrap, feature(if_let_guard))]
 #![feature(decl_macro)]
 #![feature(iter_intersperse)]
-#![feature(try_blocks)]
 #![recursion_limit = "256"]
 // tidy-alphabetical-end